Crackling/static sound from my setup

I'd start by powering down and unplugging and plugging back in all the interconnects just to check they are clean and connected properly.

Is it a constant crackling or just intermittent pops. If the latter, then it could be something like central heating - the noise from a thermostat clicking on and off for example ? 

Any new electrical equipment in the house in the last month ?

Both channels?  How long since a service?

james n posted:

I'd start by powering down and unplugging and plugging back in all the interconnects just to check they are clean and connected properly.

Is it a constant crackling or just intermittent pops. If the latter, then it could be something like central heating - the noise from a thermostat clicking on and off for example ? 

Any new electrical equipment in the house in the last month ?

Interesting thought - I’ll pay attention to see if there’s any relationship to heating (though that being gas, it shoudln’t be as much of a racket on the mains). 

It’s constant crackling for a couple of minutez, then it goes away (unless I shut it down and turn back on).

davidf posted:

Both channels?  How long since a service?

Yep, both channels, oldest service of any unit was 4 years ago (the 72), the rest have done more recently than that.

Sources ? 

Primarily LP12, but I also have a Nak tape deck connected to it.

The sound is there on every input when it happens, though.

Hmm - well as it's both channels then it's more likely to be coming from the 72 than the 135s.

Not much to go wrong in a 72 but it would be worth opening it up and making sure all the boards are seated correctly onto the main PCB. 

james n posted:

Hmm - well as it's both channels then it's more likely to be coming from the 72 than the 135s.

Not much to go wrong in a 72 but it would be worth opening it up and making sure all the boards are seated correctly onto the main PCB. 

I agree - it’s either the 72 or the SC, I guess.

I’ll crack open the 72 and see what I find.

The balance knob on my 62 went t*ts up. I seem to recall it was crackling.

Fatcat makes a good point. If you have eliminated all other possibilities it might be worth checking the volume and balance pots.  I had a fault on my 252 volume pot. The difference was that it only made the noise when volume was being adjusted.

Stu

If all looks OK inside the NAC72 then it could be a component failing on the main board - this would certainly account for crackling on both channels.  Otherwise, the ALPS remote source selector may be wearing out or dirty. Either way, it looks like you may well need some Naim service tech input.

Thanks, everyone. Yesterday I removed and reinserted every board on the 72. It hasn't done anything weird yet. Will keep watching.